import java.util.Scanner;

public class Study24 {

	public static void main(String[] args) {
		Scanner cr = new Scanner(System.in);
		System.out.println("请输入数字：");
		int num=cr.nextInt();
		int n=num;
		int sum=1;
		for(int i = 0;i<n;i++) {
			num=n-i;
			sum*=num;
		}
		System.out.println("数字阶乘得："+sum);
	}

}
